I reguarly use Vivado elaborated design view to browse RTL hierarchy. The schematic view, signal trace, etc is the best I've seen. You can also automate it with

I reguarly use Vivado elaborated design view to browse RTL hierarchy. The schematic view, signal trace, etc is the best I've seen. You can also automate it with tcl, so I've used it to auto highlight clock domains in different colours, so you can see where crossings happen, etc.